Scotiazoa lilium ( Monniot & Monniot, 1982 )

Monniot, Francoise, 2021, New records of deep-sea ascidians (Tunicata, Ascidiacea) from the New Caledonia region, Zootaxa 4996 (3), pp. 443-468 : 449

Scotiazoa lilium ( Monniot & Monniot, 1982)

Figure 6

Stations: Kanadeep CP 5095; CP 5109. Nine specimens.

Protoholozoa lilium Monniot C. & Monniot F. 1982 .

All colonies are brittle, very soft with a triangular head above a long cylindrical peduncle ( Fig. 6A ). The diameter of the head (always damaged) is about 1cm, the longest peduncle is 6 cm with 2 mm in diameter. The zooids have their thorax and abdomen contained in the transparent tunic of the head the post abdominal vascular extensions extend into the peduncle. The thorax is in vertical position for most of the zooids with the atrial aperture at the top surface of the colony and the oral siphon near the peduncle. The thoraces are narrow 6 to 8 mm long ( Fig. 6C ). The body wall is thin with circular muscles at the base of the oral siphon and with 15 transverse muscles along the thorax. There are eight to ten oral tentacles. The branchial tissue includes three transverse bars on each side attached to the endostyle and a dorsal membrane. This organisation corresponds to that of specimens from New Caledonia described as Protoholozoa lilium by Monniot & Monniot (1991, Fig. 15 ). The digestive loop encircles the hermaphrodite gonad. The ovary is anterior to the testis vesicles which are arranged in a rosette. A pedunculate brood pouch ( Fig. 6C ) is inserted at the base of the thorax and occasionally contains a single larva. The tadpole has three adhesive papillae in a triangle and one otolith ( Fig. 6B ). The larval body is 1.7 mm long encircled by the tail.

The structure of the larva is typical of the Holozoidae family. It confirms the attribution of the species to the genus Scotiazoa instead of Protoholozoa (see Monniot & Tatian 2020).

Figures

FIGURE 6. Scotiazoa lilium. A colony, scale bar = 1cm; B, larva; C, zooid.

FIGURE 15. Pyura viarecta. A, body ventrally opened; B, same body, branchial sac removed. Scale bars = 1cm.